Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
The present disclosure relates generally to devices and systems for power management such as power monitoring, control, and measurement, such as devices and systems that may be used to prevent power interruptions or improve power quality through the use of an operator-computer-controlled interface. For example, the present disclosure may find use in various types of power management devices such as power switchgear, Uninterruptable Power Supplies (UPSs), load banks, generators, Computer Room Air Conditioner (CRAC) units, Computer Room Air Handling (CRAH) units, parallel switchgear, substation switchgear, utility switchgear, and the like. More specifically, this patent disclosure concerns methods and systems for control of a power-quality measuring or monitoring devices comprising multiple bus structures.
Power-quality measuring and monitoring is an important concept in the power industry and generally relates to devices, methods, and systems that ensure that an alternating current (AC) power system is consistent, free from harmonic content, and/or remains uninterrupted. For example, a power-quality meter is one type of device that can give some form of harmonic content indication. Another example of a power-quality and monitoring device is a power transfer switch that is used to switch electrical loads between two independent sources of power, so as to prevent disruption in service. One goal of a power transfer-switch system is to help ensure that the electrical load is supplied with an acceptable source of power at a high rate of availability and to minimize load disruptions. Power transfer switches are in widespread use in, e.g., airports, subways, schools, hospitals, military installations, industrial sites, and commercial buildings equipped with secondary power sources and where even brief power interruptions can be costly or perhaps even life threatening.
Certain known methods and systems have been used for monitoring and controlling power systems. Such power systems may typically comprise a single engine generator bus with one or more paralleled engine generators operatively coupled to this single bus structure. An isolation device, such as an electric circuit breaker, an automatic transfer switch, or the like may be used to operatively couple the engine generator to the single bus. In this configuration, a monitoring system controller may be used to control the operation of the two generators, the isolation device, and the various types of different loads that are connected to the bus. Such a monitoring system controller operates so as to efficiently and economically run the generators and connect and disconnect the loads, when required. In such a single bus and parallel engine generator configuration, various control features may be used to operate the engine generators and loads during certain events. Such control features may include such features as automatic generator starting, block loading, load prioritization, under frequency conditions, bus optimization, bus overload, load demand, load control of disconnect devices, load Hand-Off-Auto, and no load system tests.
If, however, the engine generators could be paralleled together on separate buses, where each separate bus comprises two or more paralleled generators, the automated system utilized in a single bus system as described above presents certain limitations. As just one example, such an automated system may not be configured or operable so as to provide certain of the various operation and control features as noted above. As such, there is a general need for a more efficient method and system for controlling a power monitoring system comprising a plurality of parallel generator sets used on a plurality of separate busses wherein the busses are operatively coupled to a plurality of different prioritized loads.